If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

One of the downsides of direct injected motors is carbon buildup. Over time carbon builds up on the intake valves cluttering them up and having a detrimental effect on an engine's performance. Oil and fuel essentially gets on there and this creates a circular problem of more and more oil and fuel clinging to the deposits and the thickness of the deposits around the valves increases. Just how bad can this be? Just take look at how much material was removed from a B7 RS4.

That is quite a bit of material, isn't it? There is no way anyone could expect an engine to function as it should with it being gunked up with that much carbon. This car had 69800 miles on it and did not have any aggressive modifications only a rear section exhaust and filter.

As for the effect on performance, the baseline on a Mustang all wheel drive dyno before the cleaning showed 287 horsepower to the wheels and 240 pound-feet of torque to the wheels. After the cleaning these figures change to 329 horsepower and 266 pound-feet of torque. A night and day difference.

There are measures that can be taken to minimize carbon buildup such as oil catch cans and methanol injection but this will be an issue no matter what and one owners of direct injected engines should monitor. A good cleaning can make the car feel like new especially if one gets the impression it has become sluggish over time.

I believe it. I've spent some time on the big carbon buildup threads for RS4s. Crazy stuff. These are amazing engines but the carbon buildup is almost beyond belief. If I had one I'd have meth and a catch can and I'd drive the piss out of it every possible chance in order to minimize it...this must be an expensive process.

If all that carbon was put inside the intake ports, the size of the ports would be considerably reduced and would hardly let any air through. Maybe the carbon is accumulating somewhere else too? That is a $#@!load of carbon compared to what is on the intake port picture.

Perhaps I should have said it this way: there is no way all that carbon is coming from the intake ports of one motor. I'd like to know where the carbon is also building up. Anyways, time for this kid to go to bed.

I cannot tell how big the tray is but I would say 99% that the carbon is not from the motor of which the valves are pictured. In my opinion and I could be wrong there isnt enough carbon on the valves pictured to allow scooping of the carbon. Also when its so little carbon the port dividers which gather a lot of carbon have a very thin surface.

I cannot tell how big the tray is but I would say 99% that the carbon is not from the motor of which the valves are pictured. In my opinion and I could be wrong there isnt enough carbon on the valves pictured to allow scooping of the carbon. Also when its so little carbon the port dividers which gather a lot of carbon have a very thin surface.

The N54 is an engine that runs very very dirty too. My last N54 had to get cleaned at 50k cus it couldn't even do a pull at 13psi without coughing like a bad smoker leading to SES lights all the time. My 2nd N54 is up for a clean up, the car is now sitting at 61k miles, I can't even imagine how bad the valves look already, but this maintenance is not cheap, which sucks even more.

The N54 is an engine that runs very very dirty too. My last N54 had to get cleaned at 50k cus it couldn't even do a pull at 13psi without coughing like a bad smoker leading to SES lights all the time. My 2nd N54 is up for a clean up, the car is now sitting at 61k miles, I can't even imagine how bad the valves look already, but this maintenance is not cheap, which sucks even more.

Labour is cheap in South Africa, we do N54/55's for $250 inclusive of gaskets.